cardio drugs Flashcards
moA of ivabradine
selective blocker of HCN channels, reduces the slope of pacemaker potential - slow HR reduces oxygen consumption
what is ivabradine used to treat
angina, tachycardia, mild to moderate chronic heart failure
side effects of ivabradine
arrhythmias and hypotension
what are dobutamine, adrenaline and Noradrenaline
b - adrenoceptor agonists
moA of b - adrenoceptor agonists
results in stimulation of adenylyl cyclase and production of cAMP which generates protein kinase A. Phosphorylation increases Ca influx and release of Ca from sacroplasmic reticulum increase contractility, force and rate and decrease cardiac efficiency
when are beta adrenoceptors used
in infarction, cariogenic shock, cardiomyopathy, inotropic support, heart failure (dobutamine), asthma emergency (adrenaline), anaphylactic shock
SE of beta adrenoceptors
arrhythmias and acute MI
what is dobutamine
selective for B 1
b1 selective b blockers
metoprolol, atenolol
what are propanolol, metoprolol, atenolol
beta blockers
MoA of beta blockers
decrease HR, contractility, MAP and O2 consumption
when are beta blockers used
angina, hypertension, heart failure, thyrotoxicosis
SE of beta blockers
asthma, fatigue, cold peripheries, HF - in patients with cardiac failure who rely on sympathetic drive to maintain CO, bradycardia and hypoglycaemia
what is atropine
a muscularinic antagonist
what does atropine do
it is non selective for M2 receptors and increases HR
when to use atropine
reverse bradycardia following MI, adjunct to anaesthesia, anti cholinesterase poisoning (reduces parasympathetic)
SE of atropine
arrhythmias, hallucinations, confusion
what is digoxin
a cardiac glycoside
Moa of digoxin
competes with K at alpha submit and blocks the Na/K pump
what does digoxin cause
increased contractility bu blocking the sarcolemma ATPase, indirectly increases vagal activity slowing SA node discharge and directly shortens action potential and refractory period increasing force, contraction and CO - effects are dangerously enhanced with hypokalaemia
when to use digoxin
HF, AF
SE of digoxin
Heart block, dysrhythmias, myocarditis
what is levosimendan
calcium sensitizer
moA of levosimendan
binds to troponin C in myocytes sensitising them to Ca
when to use levosimendan
acutely decompensated congestive heart failure and increased contractility
SE of levosimendan
headaches, arrhythmias and hypokalaemia
what is flecainide
a class I antiarrhythmic
what does a class 1 antiarrhythmic do
acts on voltage gated Na channels reducing Na channel current
when is flecainide used
for rhythmic control
SE of flecainide
negative inotropic effects
what are beta adrenoceptors
class II antiarrythmics
examples of beta adrenoceptors
propanalol
what are class II antiarryhtmics used for
rate control
what is amiodorane and sotalol
class III antiarhymic
MoA of class iii antiarryhtmics
voltage gated K channels
what do class iii anti arrhythmics do
lead to action potential prolongation
when are class iii anti arrhythmics used
for rhythm control
class IV drug example
verapamil
Moa of verapamil
calcium channel blocker
what is verapamil used for
rate control
what are isorbide mononitrate and GTN spray
nitrates
what do nitrates do
mimic the effect of the endothelium, produce nitric oxide which is formed through influx of Ca activation of eNOS and L -argine and NO caused efflux of Ca producing hyper polarisation and relaxation, Endothelin is also produced
what do nitrates cause
venorelaxation (decreased preload and after load, CO maintained as HR increases arteriolar dilation and increased coronary blood flow